![]() In 2002 Fox was interviewed by David Wolman for an article in New Scientist, where he stated that he did not believe its origin was man-made, such as a submarine or bomb. NOAA's Christopher Fox, in an interview with CNN in 2001, stated that he believed Bloop to be ice calving in Antarctica. The acoustical signals emitted by this failure process are similar to those emitted from a collapsing air bubble in a fluid." : 121 Animal origin "A wave equation resulting from shear deformation will be defined in an ice floe with the rubbing effect coupled to the floe through its boundary with the adjacent ice," : 137 while "ridging deformation(s) revealed by this event indicate that the failure process is associated with a crushing process that seals air or vacuous gaps between ice floes. : 121 According to Xie, both events will produce sound in the failure sequence (breakup) of an ice floe: ![]() : 137 Ridging occurs when that ice bends or slides at the ridges. Rubbing involves two or more areas of compacted glacial ice floes which are being forced together, inducing shear deformation at its edges and triggering horizontally-polarized shear waves, i. Two processes known as rubbing and ridging are responsible for acoustical emissions similar to those from ice calving. : 55 As oceanographer Yunbo Xie explains, the alteration of waveforms from a detected sound "can also be caused by so-called angular frequency dependent radiation patterns associated with antisymmetric mode motion of the ice cover." : 59 Rubbing and ridging events within an ice floe In ice calving, variations result from a sound source's own motion. Sounds generated by ice quakes are easily determined through the use of hydrophones since sea water, an excellent sound channel, allows the ambient sounds generated through ice activities to travel great distances. The iceberg(s) involved in generating the sound were most likely between Bransfield Straits and the Ross Sea or possibly at Cape Adare, a well-known source of cryogenic signals. This was found during the tracking of iceberg A53a as it disintegrated near South Georgia Island in early 2008. Numerous ice quakes share similar spectrograms with Bloop, as well as the amplitude necessary to detect them despite ranges exceeding 5000 km. The NOAA Vents Program has attributed the sound to that of a large cryoseism (also known as an ice quake). Problems playing this file? See media help.Īccording to the NOAA description, the sound "rose" in frequency over about one minute and was of sufficient amplitude to be heard on multiple sensors, at a range of over 5,000 km (3,000 mi). Navy Sound Surveillance System ( SOSUS), which was equipment originally designed to detect Soviet submarines. : 284 This is a stand-alone system designed and built by NOAA's Pacific Marine Environmental Laboratory (PMEL) to augment NOAA's use of the U.S. The sound was detected by the Equatorial Pacific Ocean autonomous hydrophone array, a system of hydrophones primarily used to monitor undersea seismicity, ice noise, and marine mammal population and migration. The sound's source was roughly triangulated to 50°S 100°W / 50°S 100°W / -50 -100 Coordinates: 50°S 100°W / 50°S 100°W / -50 -100, a remote point in the south Pacific Ocean west of the southern tip of South America. By 2012, earlier speculation that the sound originated from a marine animal was replaced by NOAA's description of the sound as being consistent with noises generated via non-tectonic cryoseisms originating from glacial movements such as ice calving, or through seabed gouging by ice. National Oceanic and Atmospheric Administration (NOAA) in 1997. Bloop was an ultra-low-frequency, high amplitude underwater sound detected by the U.S.
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